TRURO, Mass. — The Massachusetts beach where a man was bitten while swimming remains open as authorities try to determine whether it was a shark that attacked him.

The Executive Office of Environmental Affairs said Tuesday it is gathering information about the Monday incident at Ballston Beach in Truro but cannot yet confirm what caused the swimmer's wounds.

Fire Chief Brian Davis says the man, identified by the Cape Cod Times as Christopher Myers, has severe cuts on both legs but will not lose a limb. He was taken to Cape Code Hospital then transferred to Massachusetts General Hospital in Boston.